Published in 1951 in a post-nuclear world, this short story by Arthur C. Clarke takes its title from a portion of Psalm 137, which laments the destruction of Jerusalem in 597 B.C. Much like Jerusalem, which was overrun and destroyed by the Babylonians, the actions of nuclear war have destroyed the Earth in this story, leaving 10-year-old Marvin and a small band of other humans to look on the ruins of Earth from their small colony on the moon. Clarke, a scientist himself, creatively utilizes the science fiction genre to paint a horrifying picture of what the potential destructiveness of advancements in war and weaponry could do to humanity’s future.
Marvin is 10 years old, and his father is taking him through the different levels of the Colony to a place he’s never been before: Outside. They hop into a little scouting vehicle with a pressurized cabin and take off away from the Colony.
Marvin has never before seen the Outside, and he wonders where his father is taking him. Everything he knows about the Outside has come from books. He wonders why an old book of his father’s has the rhyme, “Twinkle, twinkle, little star, How I wonder what you are” in it when the stars are steady specks of light.
As Marvin and his father leave the plateau with the colony on it behind, they enter a darkened world surrounded by high mountains. Marvin is nervous as they pass a crashed rocket and darkened paths. He observes that his father is driving like he’s trying to escape from something.
Finally, after hours of driving, Marvin sees something strange. A silver crescent floats over the horizon, and it is not the sun. Marvin realizes that this is Earth, and it is awash in the glow of the sun; he is seeing Earth from the moon. However, there is also a glow in the darker parts of the Earth from the nuclear war that destroyed it.
Marvin’s father tells him the story about the days of despair that followed the war, when the people of the Colony realized they were alone. As he speaks, Marvin realizes that the people of the Colony bring their children there for a purpose: to show them that eventually, one day, after the nuclear fallout has decayed, they need to return home.
As they drive back to the Colony, Marvin can’t look behind him. He feels the desolation of exile because he knows he will never get to go home; however, he also understands his purpose: to have children, to show them Earth, and to eventually get the human race back home.